New Delhi, Sep 19 : While medical imaging can be lifesaving, an alarming study showed that one in 10 blood cancers in children is driven by exposure to radiation from medical imaging.

Medical imaging saves lives by enabling timely diagnosis and effective treatment, but it also exposes patients to ionising radiation -- a known carcinogen -- particularly through computed tomography (CT).

Researchers from the University of California, San Francisco and Davis examined data from nearly four million children and estimated that some 3,000 cancers in all may be attributable to radiation exposure from medical imaging.

The risk increased proportionally based on the cumulative amount of radiation the children received, revealed by the study appearing in The New England Journal of Medicine.

"Children are particularly vulnerable to radiation-induced cancer due to their heightened radiosensitivity and longer life expectancy," said Rebecca Smith-Bindman, radiologist and professor of Epidemiology and Biostatistics, at UCSF.

The findings underscore the critical need to carefully evaluate and minimise radiation exposure during paediatric imaging.

"This involves ensuring that imaging is performed only when it provides essential information for the child's care and, in cases such as CT scans, using the lowest possible radiation doses," said Smith-Bindman.

The researchers cautioned that doctors and parents should avoid excessive radiation doses and minimise exposure when clinically feasible.

The study used a retrospective cohort design, looking back at the complete imaging histories of 3.7 million children who were born between 1996 and 2016.

Investigators found a significant relationship between cumulative radiation dose and the risk of a hematologic malignancy -- which includes tumours affecting the blood, bone marrow, lymph, and lymphatic system.

For children who underwent a head CT, the researchers attributed about a quarter of the children's subsequent hematologic malignancies to radiation exposure.

For those who had radiographs, by contrast, they estimated that only a small fraction of the children's subsequent cancers were associated with radiation exposure.

Getting one or two head CTs was associated with a 1.8-fold increased risk of a cancer diagnosis, and this rose to 3.5 times for children who received more scans and were therefore exposed to more radiation.

Lymphoid malignancies accounted for 79.3 per cent, while myeloid malignancies and acute leukemia together accounted for 15.5 per cent. About 58 per cent of cancers occurred in males, and about half were diagnosed in children under 5.

/IANS